1. Field of the Invention
This invention relates to an electrical connector used for electrically connecting a circuit substrate such as IC card storing key words, computer program or the like, to the equipment main body mounting a computer.
An IC card is a package structure leading out the contacts provided on one side of a circuit substrate mounting an integrated circuit to the outside, and by inserting this IC card into the connector, the circuit substrate of the IC card is electrically connected to the main printed wiring substrate. The electrical connector having such action is generally known as the one corresponding to the ROM card used in the conventional television game machine or the like, but recently, as the credit card or the like, the IC card having the contacts to contact with the equipment main body as mentioned above have been introduced, and the electrical connector comes to be used widely also for such IC card.
2. Description of the Prior Art
Conventional examples of thus used electrical connector are shown in FIG. 12 and FIG. 13.
The electrical connector shown in FIG. 12 is constituted as follows: as a ROM card 103 is inserted into a card inlet 102 provided in a body 101, a curved contact 106 formed in a contact piece part 105 of a conductor piece 104 built in said body 101 is pushed away outward as indicated by the arrow while rubbing against a ROM card 107, and when the ROM card 103 is inserted in the setting position, said contact 106 elastically abuts against the contact of the ROM card 103.
In the connector shown in FIG. 12, however, when it is attempted to conduct securely by firmly fitting the contact 106 of the conductor piece 104 against the contact of the ROM card 103, a large inserting force is needed to insert the ROM card 103, and the inserting operation becomes difficult, and also when inserting or drawing out the ROM card 103, the contact of the ROM card 103 and the contact 106 of the conductor piece 104 rub against each other firmly, so that the both or either contact may be abraded to deteriorate the performance. To the contrary, when it is attempted to restrict the deterioration of quality by reducing the contacting force of the contact piece part 105 of the conductor piece 104, the contact pressure between contacts becomes small, and failure in conduction is likely to occur. Accordingly, in the eletrical connector shown in FIG. 12, in order to minimize the deterioration of quality of contact and to maintain a satisfactory conduction, it is necessary not only to properly set the contacting force of said contact piece part 105, but also to use an expensive high performance spring material for the conductor piece 104 and increase the thickness of plating layer of the contact 106, which caused to raise the cost. Incidentally, since the ROM card 103 is pulled out of the connector when not in use, it is inserted and pulled but frequency, and the deterioration of quality of contact was actually significant in spite of the above measures.
In another conventional example of electrical connector shown in FIG. 13, when an extending member 207 disposed on a body 201 is rotated in one direction by a specified angle (for example, 90 degrees) and a conductor piece 204 held in said body 201 is pushed away outward, resisting the elasticity, the contact of the ROM card 203 does not rub agaisnt the contact 206 of the contact piece part 205 when the ROM card is inserted from the inlet 202, by inserting the ROM card 203 into the setting position and rotating said extending member 207 in the reverse direction as shown by a virtual line by a specified angle, the contact 206 is returned to the original position by the elasticity of the contact piece part 205 of said conductor piece 204, so that the contact 206 elastically contacts with the contact of the ROM card 203.
In this electrical connector shown in FIG. 13, when the contact piece part 205 of the conductor piece 204 is pushed away outward by the extending member 207, the contact does not rub against the contact 206 of the conductor piece 204 when inserting the ROM card 203, so that said deterioration of quality due to abrasion of the contact may be restricted if attempted to conduct securely by increasing the contacting force of the conductor piece 204. In this electrical connector, however, the extending member 207 and various parts for operating it are necessary, and the strcuture is complicated. Still more, strcuturally, since the preload state is the maximum spring displacement state, it is required to select a high power spring that is not exhausted easily or design the spring adequately. Furthermore, since the extending member 207 must be operated every time the ROM card 203 is inserted or pulled out, and its operation is very troublesome.
In the above examples of prior art, the contact for ROM card are shown, but similar contacts are used also for RAM card and other IC cards having contacts. And the same problems will occurs in other IC cards having such connectors and contacts, and the further secure quality assurance and simplification of opertion are needed in the IC cards used as credit cards or the like reduced to the size of a visiting card, in particular.
The present applicant already proposed a connector for printed circuit board capable of solving part of the above problems in the U.S. patent application No. 873,663, but, as stated above, as the electrical connector used in IC card or the like, securer quality assurance and simpler operation are required, and the connector proposed in said U.S. patent application No. 873,663 must be further improved.